The present invention relates to a circuit breaker with an actuating device and an energy accumulator which contains at least one spring, is braced against a support mechanism of the circuit breaker and comprises a push rod serving for introducing a tensioning force and for passing-on the accumulator force.
A circuit breaker of this type has become known, for instance, from European Pat. No. EP-A-0 088 215. The spring is realized there as a compression coil spring, the turns of which enclose two guide rods which can be moved relative to each other in the longitudinal direction of the spring and of which one acts as a push rod in the direction of the actuating parts of the circuit breaker while the other guide rod serves for bracing and holding the spring arrangement against the support mechanism of the circuit breaker. To this end, a bolt, for the passage of which an opening in the support mechanism of the circuit breaker is provided, is connected to the further guide rod. The spring arrangement can be fastened by a pin which can be inserted on the back side of the support mechanism into a transverse hole of the bolt.
The installation of an energy accumulator of this type in a circuit breaker makes it necessary to mount the compression springs on the guide rods and to fasten this arrangement by means of the bolt and the transverse pin to the support mechanism of the circuit breaker.
Subsequently the spring must be tensioned so that the spring arrangement can be brought into engagement with the actuator parts. This process is difficult to carry out because, due to the compact design of modern circuit breakers, only little space is provided for the engagement of fixtures or tools. On the other hand, there is the danger of damaging or injuring already built-in parts of the circuit breaker if an error is made when tensioning the springs due to poor accessibility and the spring slips off the tool or fixture used before the spring force is safely intercepted.